CN114297782A

CN114297782A - Load spectrum processing method, device, equipment and storage medium

Info

Publication number: CN114297782A
Application number: CN202111653354.2A
Authority: CN
Inventors: 袁文强; 李妮妮; 辛强; 郭鹏鹍; 周倩瑶; 姜洋; 王秋敏
Original assignee: Crat Testing & Certification Co ltd; Guangzhou Mechanical Engineering Research Institute Co Ltd
Current assignee: Crat Testing & Certification Co ltd; Guangzhou Mechanical Engineering Research Institute Co Ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-04-08

Abstract

The invention provides a load spectrum processing method, a device, equipment and a storage medium, wherein the method comprises the following steps: collecting a load spectrum of the automobile part, and performing cyclic statistics, penetration counting and other processing on time domain loads in the load spectrum to generate a primary equivalent load block spectrum; and respectively calculating the pseudo damage values of the load spectrum and the initial equivalent load block spectrum, and correcting the initial equivalent load block spectrum according to the pseudo damage values to obtain the equivalent load block spectrum. According to the technical scheme, when the random load spectrum is converted into the equivalent load block spectrum, the influences of the average value and the maximum value of the load and the phase relation among a plurality of loads are considered, so that the equivalence of the equivalent load loaded in the endurance test of the automobile part is improved, and meanwhile, the accuracy of the endurance test result is improved; the fatigue endurance test process of the automobile parts is simplified, and the time cost is saved.

Description

Load spectrum processing method, device, equipment and storage medium

Technical Field

The invention relates to the technical field of automobile endurance tests, in particular to a load spectrum processing method, device, equipment and storage medium.

Background

In order to verify the fatigue performance of the automobile structural part, a part fatigue endurance test needs to be carried out in the development process, and a test field road test needs to be carried out by assembling the parts on a sample car. In the fatigue endurance test process of the part, the accuracy of the input load directly influences the effectiveness of the test. Therefore, the random load spectrum needs to be converted into a block spectrum consisting of a plurality of sine wave load spectrums for loading, and the block spectrum has the characteristics of simple loading, short test time and the like; this process of converting the random spectrum into a block spectrum by some method is called load equivalence.

However, in the above prior art, in the conversion process of converting the random load spectrum into the block spectrum, the influence of the maximum load is ignored because the influence of the average value is not considered, but the damage caused by the maximum load is the largest; or when a plurality of loads are loaded simultaneously, the problem of phase relation of the plurality of loads is not considered, so that the equivalence of equivalent loads input by an endurance test is influenced, and the accuracy of the endurance test result is reduced.

Disclosure of Invention

In view of the above, the present invention provides a load spectrum processing method, apparatus, device and storage medium to overcome the disadvantages in the prior art.

In a first aspect, the present invention provides a load spectrum processing method, including:

acquiring a load spectrum of a part in an automobile, wherein the load spectrum comprises a plurality of groups of time domain loads;

carrying out cycle statistics on the time domain load by adopting a four-point method to obtain a load range amplitude and cycle times;

performing level-through counting on the time domain load to obtain an average value of equivalent loads corresponding to the time domain load, and determining a preliminary equivalent load block spectrum according to the load range amplitude, the cycle times and the average value;

and correcting the primary equivalent load block spectrum to obtain an equivalent load block spectrum.

In one embodiment, the loading spectra include unidirectional loading spectra and multidirectional loading spectra.

In an embodiment, before performing cycle statistics on the time-domain load by using a four-point method to obtain a load range amplitude and a cycle number, the method further includes:

acquiring a first load value of the time domain load at a time point, and a second load value and a third load value of a front time point and a rear time point corresponding to the time point;

and if the first load value, the second load value and the third load value form an increasing or decreasing relation, deleting the first load value.

In an embodiment, when the load spectrum is a unidirectional load spectrum, performing cycle statistics on the time-domain load by using a four-point method to obtain a load range amplitude and a cycle number includes:

determining a cycle composition of each group of the time domain loads by adopting a four-point method, wherein each cycle in the cycle composition comprises two load data points in the time domain loads;

calculating the difference value between the load values of the load data points forming each cycle in the cycle composition, and taking the difference value as the load range amplitude of each group of the time domain load;

and cumulatively counting the cycle composition according to the amplitude of the load range to obtain the cycle times.

In an embodiment, the modifying the preliminary equivalent payload block spectrum to obtain an equivalent payload block spectrum includes:

calculating a first pseudo damage value of the load spectrum and a second pseudo damage value of the primary equivalent load block spectrum by adopting a preset pseudo damage calculation formula;

comparing the first pseudo damage value with the second pseudo damage value to obtain a comparison result;

and adjusting the equivalent load block spectrum according to the comparison result to obtain the equivalent load block spectrum.

In an embodiment, when the load spectrum is a multi-directional load spectrum, performing cycle statistics on the time-domain load by using a four-point method to obtain a load range amplitude and cycle times includes:

calculating the synthesis coefficient of each time domain load in the multi-directional load spectrum according to a preset synthesis coefficient calculation formula;

calculating a first synthesized load corresponding to each group of the time domain loads according to the synthesized coefficient;

performing cycle statistics on the first synthesized loads by adopting a four-point method to obtain the cycle composition of each group of the first synthesized loads;

and calculating the load range amplitude and the cycle times of the equivalent load corresponding to the time domain load in each direction in the multi-direction load spectrum according to the cycle composition.

adjusting the phase relation among equivalent loads corresponding to the time domain loads in each direction, and calculating a second synthesized load corresponding to the equivalent loads according to the phase relation and the synthesis coefficient;

calculating a third pseudo damage value of the first composite load and a fourth pseudo damage value of the second composite load according to the pseudo damage calculation formula;

and adjusting the preliminary equivalent load block spectrum according to the phase relation, the third pseudo damage value and the fourth pseudo damage value to generate an equivalent load block spectrum with a phase relation.

In a second aspect, the present invention provides a load spectrum processing apparatus, the apparatus comprising:

the system comprises an acquisition module, a processing module and a control module, wherein the acquisition module is used for acquiring a load spectrum of a part in an automobile, and the load spectrum comprises a plurality of groups of time domain loads;

the statistical module is used for performing cycle statistics on the time domain load by adopting a four-point method to obtain a load range amplitude and cycle times;

the determining module is used for carrying out grading counting on the time domain load to obtain an average value of equivalent loads corresponding to the time domain load, and determining a preliminary equivalent load block spectrum according to the load range amplitude, the cycle times and the average value;

and the correcting module is used for correcting the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum.

In a third aspect, the present invention provides a load spectrum processing apparatus comprising a memory storing a computer program and at least one processor for executing the computer program to implement the load spectrum processing method described above.

In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program which, when executed, implements the load spectrum processing method described above.

The embodiment of the invention has the following advantages:

according to the technical scheme, a time domain load in a load spectrum is subjected to cyclic statistics, penetration counting and other processing to generate a primary equivalent load block spectrum, pseudo damage values of the load spectrum and the primary equivalent load block spectrum are calculated respectively, and the primary equivalent load block spectrum is corrected to obtain an equivalent load block spectrum; for multi-directional loads, the technical scheme of the invention also determines the phase relation of equivalent loads in all directions by comparing the pseudo-damage distribution conditions of the composite load of the time domain load and the composite load of the equivalent load, thereby converting a random load spectrum into an equivalent load block spectrum, improving the equivalence of the equivalent load loaded by an automobile part endurance test, and simultaneously improving the accuracy of an endurance test result; the fatigue endurance test process of the automobile parts is simplified, and the time cost is saved.

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible and comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic diagram of an embodiment of a load spectrum processing method according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating a cyclic accumulation result of a unidirectional time domain load according to an embodiment of the present invention;

FIG. 3 is a graph illustrating a result of a hierarchical count of time-domain loads in an embodiment of the present invention;

FIG. 4 is a schematic diagram of another embodiment of the load spectrum processing method in the embodiment of the present invention;

FIG. 5 is a graph of the cyclic accumulation of load 1 in the embodiment of the present invention;

FIG. 6 is a graph of the cyclic accumulation of load 2 in the embodiment of the present invention;

FIG. 7 is a graph showing the result of the counting of the load 1 in the embodiment of the present invention;

FIG. 8 is a graph showing the result of the counting of the load 2 in the embodiment of the present invention;

FIG. 9 is a diagram illustrating the pseudo-impairment values of all the composite loads of the time-domain load A according to an embodiment of the present invention;

FIG. 10 is a schematic diagram illustrating a pseudo-damage value of a combined load of each channel when a phase difference between two equivalent loads is 150 degrees according to an embodiment of the present invention;

fig. 11 is a schematic diagram of an embodiment of a load spectrum processing apparatus in an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the templates herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Example 1

Referring to fig. 1, the present embodiment provides a load spectrum processing method, and the following describes the equivalent load block spectrum processing method in detail.

101, collecting multiple groups of time domain loads of parts in an automobile;

in order to verify the fatigue performance of the automobile structural member, a part fatigue endurance test needs to be performed during the development process, and a test field road test needs to be performed by assembling the part on a sample car. In the fatigue endurance test process of the part, the accuracy of the input load directly influences the effectiveness of the test. In the initial development stage of the part, the main sources of input loads include: and extracting the empirical load and the load virtual under the standard working condition or extracting the load of the virtual road surface. After the sample car is assembled, input loads are acquired from a test field load spectrum, some parts with simple structures can directly obtain accurate loads through calibration, part parts are inconvenient to directly carry out load acquisition, load decomposition is carried out through simulation of a sample car multi-body dynamic model, and loads of the parts can be extracted.

After the load spectrum on the loading point of the automobile upper part, namely the concerned part, is obtained, the load spectrum can be processed and converted into a sine-wave load. In a general automobile endurance test, an acquired or extracted load spectrum comprises a plurality of groups of time domain load data, and each group of load needs to be repeatedly loaded for a certain number of times during the test. Each group of time domain loads is composed of a series of (multi-channel) equally spaced numerical points representing the magnitude of the load. Each channel represents a load in a different direction or load at a different load point. After the load spectrum on the loading point of the part of the automobile is obtained, the load spectrum can be processed and converted into a sine-wave load.

The part in the automobile can be subjected to unidirectional load or multidirectional load, namely the acquired load spectrum of the part in the automobile comprises a unidirectional load spectrum and a multidirectional load spectrum. The following description will be made by taking a unidirectional load spectrum as an example.

102, performing cycle statistics on the time domain load by adopting a four-point method to obtain a load range amplitude and cycle times;

before performing cyclic statistics on the time domain load by adopting a four-point method, a first load value of the time domain load at a time point, and a second load value and a third load value of a front time point and a rear time point adjacent to the time point are required to be obtained; judging whether the first load value, the second load value and the third load value form an increasing or decreasing relation; if an increasing or decreasing relationship is formed, the first load value is deleted. That is, data points which are not the inflection points in each group of time domain loads are removed, only the inflection points are reserved, and if the load value of the time domain load at a certain time point and the load values at the time points before and after the time point form an increasing or decreasing relationship, the load value at the time point can be removed. If the load value of the time-domain load at a certain time point is simultaneously greater than or simultaneously less than the load values at the previous and subsequent time points, the load value at the time point is an inflection point and needs to be reserved.

The time domain load with the non-inflection points removed is divided into two sections from the maximum point of the absolute value, and then the first section is connected to the end of the second section. Although the time sequence of the time domain load is omitted in the above processing, the processing is used as an equivalent processing, and the loop recognition procedure can be simplified. Then, a four-point method is adopted to carry out cycle statistics on the time domain load, namely, the load cycle is identified, and the identification method is as follows:

(1) determining four load data points in time-domain load, e.g. S, in turn_i、S_i+1、S_i+2And S_i+3If min (S)_i，S_i+3)≤min(S_i+1，S_i+2) And max (S)_i，S_i+3)≥max(S_i+1，S_i+2) Then, it is considered as S_i+1To S_i+2Forming a loop, recording the loop and dividing S_i+1、S_i+2These two data points are removed from the sequence of time domain loads.

(2) Data point S_i+1、S_i+2After removal, judge S_iFront isIf no data point remains, if only one data point S exists_kThen the data point S is set_kAnd S_i、S_i+3And S_i+4And (4) recombining four points and identifying by the method in (1). Data point S_i+1、S_i+2After removal, if S_iIf more than one data point is left before, it will be closest to S_iTwo data points S_m，S_kAnd S_i、S _i+3And (5) recombining four points and identifying by using the method in the previous step.

(3) If S is_i、S_i+1、S_i+2And S_i+3If the judgment condition in (1) is not satisfied, S is set_i+1、S_i+2、S_i+3And S_i+4And combining the four points to carry out cycle identification.

After cyclic identification is carried out on the time domain loads by adopting a four-point method, cyclic composition of each group of the time domain loads can be determined, wherein each cycle in the cyclic composition comprises two load data points in the time domain loads.

Further, after the cyclic composition of the time-domain load is obtained, the equivalent load corresponding to the time-domain load can be calculated according to the cyclic composition, and the difference value of the two load data points forming each cycle is used as a first load range amplitude value, wherein the first load range amplitude value is a first load range. Processing each group of time domain loads in sequence, then forming a cycle identified from each group of time domain loads, counting according to the first load range from large to small in an accumulated mode, simultaneously considering the loading times of each group of time domain loads (each group of time domain loads needs to be loaded repeatedly for a certain time, wherein the loading times can be preset), obtaining an accumulated cycle time, and taking the accumulated cycle time as the first cycle time to obtain a load range-accumulated cycle time curve graph (a cycle accumulation result graph).

Dividing the load range-accumulated cycle number graph into a plurality of sections according to the accumulated cycle number, and estimating the average value of the cycle load range of each section. The average value is used as the load range of the equivalent load of the corresponding load section, the accumulated cycle number of each section is used as the cycle number of the equivalent load, the equivalent load range is used as the amplitude of the second load range or the second load range, and the cycle number of the equivalent load is used as the second cycle number.

As shown in fig. 2 (a graph of the cyclic accumulation result of the unidirectional time domain load), the curve is divided into several segments according to the load range in the graph, and the division into five segments (only the first four segments are calculated) is exemplified here, that is, the curve is segmented at 100 times, 1000 times, 10000 times and 100000 times of the accumulated cyclic times respectively. Then, the average load range of each segment is roughly determined according to the load range of each segment, for example, the load ranges respectively corresponding to the horizontal straight lines approximated by the four previous segments of curves in fig. 2 represent the average load range of the segment, so as to determine the range of the equivalent load block spectrum and the corresponding cycle number, that is, the average load range of each segment is used as the equivalent load range of the equivalent load block spectrum, and the cumulative cycle number corresponding to the average load range is used as the cycle number of the equivalent load, as shown in table 1.

TABLE 1 equivalent load Range and number of cycles

Serial number	Equivalent load range (N)	Number of cycles (times)
			1	23800	100
2	17500	900
			3	9200	9000
4	5000	90000

103, carrying out through-grade counting on the time domain load to obtain an average value of the equivalent load corresponding to the time domain load, and determining a preliminary equivalent load block spectrum according to the load range amplitude, the cycle times and the average value;

and after the non-inflection point load values are removed, performing cross-level counting on the time domain load. The load values are classified by a certain interval size based on the full range of the load value distribution, for example, the load values are distributed between-16000N and +13000N, and-16000N to +13000N are classified into one class every 100N. When the load value of the time-domain load rises from one level to another, the cumulative count at the corresponding level is increased by one, and only the number of times the time-domain load passes through the level during the increase of the load value is recorded. After the groups of time domain loads needing to be loaded in the endurance test are sequentially counted, the loading times of each group of time domain loads are considered, the grading counting results are merged and summarized, and the obtained statistical result is shown in fig. 3 (a grading counting result graph of the time domain loads).

And segmenting the penetration times according to the segmentation times in the load range-accumulated cycle time curve chart, and estimating the average value of the load values of each segment of time domain load, wherein the average value is used as the average value of the equivalent load of the segment of load. As shown in fig. 3, the results of the classification counting were segmented at 100 times, 1000 times, 10000 times and 100000 times, respectively, and the average value of the load of each segment was estimated, and the results are shown in table 2.

TABLE 2 equivalent load Range, average and number of cycles

Serial number	Equivalent load range (N)	Mean value (N)	Number of cycles (times)
				1	23800	-1500	100
2	17500	0	900
				3	9200	-1000	9000
4	5000	-1200	90000

And generating a preliminary equivalent load block spectrum according to the second load range, the second cycle number and the average value of the equivalent load.

104, correcting the primary equivalent load block spectrum to obtain an equivalent load block spectrum;

and (4) carrying out cycle identification on the time domain load by adopting a four-point method to obtain the cycle composition of the time domain load. According to a preset pseudo-damage value calculation formula, namely a fatigue damage linear accumulation hypothesis rule (a miner rule), the pseudo-damage values of the preliminary equivalent load block spectrum and the time domain load spectrum (load spectrum) can be calculated, wherein the pseudo-damage value of the time domain load spectrum is used as a first pseudo-damage value, and the pseudo-damage value of the preliminary equivalent load block spectrum is used as a second pseudo-damage value.

The formula for calculating the false damage value without considering the mean value correction is as follows:

D_i＝n_i×S_i ^m/10⁷

wherein D_iIs a false damage of load cycle i; n is_iIs the number of cycles of the load cycle i; s_iIs the amplitude of the load cycle i, which is equal in value to half the amplitude of the load range of the load cycle i (load range); m is a parameter related to material properties, sample form, stress ratio, loading mode and the like, common metal parts in automobiles, and the recommended value of m is 3-7.

According to the above method for calculating the pseudo damage value, the result of calculating the pseudo damage value of the equivalent load in table 2 is shown in table 3 (in the process of calculating the pseudo damage value in table 3, m is set to be 5), that is, a second pseudo damage value is calculated according to the second load range and the second cycle number:

TABLE 3 pseudo damage values for equivalent loads

According to the above method for calculating the pseudo-damage value, the pseudo-damage value of the load cycle of the time domain load can be calculated as well, that is, the first pseudo-damage value is calculated according to the first cycle number and the first load range, as shown in the time domain load accumulation cycle result shown in fig. 2, and the calculation result of the pseudo-damage value is shown in table 4.

TABLE 4 pseudo-impairment values of time-domain loading

And comparing a first pseudo damage value of the time domain load spectrum with a second pseudo damage value of the preliminary equivalent load block spectrum, and if a larger difference exists between the first pseudo damage value and the second pseudo damage value, namely the difference value between the first pseudo damage value and the second pseudo damage value is larger than a preset threshold value, correcting the preliminary equivalent load block spectrum according to the first pseudo damage value and the second pseudo damage value to obtain the equivalent load block spectrum, wherein the preset threshold value can be set according to actual conditions, and no limitation is made herein.

Further, when a large difference exists between the first pseudo damage value and the second pseudo damage value, the value of the equivalent load range of the equivalent load is continuously adjusted, namely the value of the second load range is adjusted to obtain a third load range, a fifth pseudo damage value of the preliminary equivalent load block spectrum is obtained through calculation according to the third load range and the second cycle number, and when the difference between the fifth pseudo damage value and the first pseudo damage value is smaller than a threshold value, the equivalent load block spectrum can be generated according to the third load range, the second cycle number and the average value of the equivalent load.

According to the calculation result of the pseudo damage value of the time domain load (see table 4) and the calculation result of the pseudo damage value of the equivalent load (see table 3), the equivalent load range with large difference of the pseudo damage value is corrected, and the corrected equivalent load block spectrum is shown in table 5.

TABLE 5 modified equivalent load Block spectra

As an alternative embodiment, referring to fig. 4, a multi-directional load spectrum is taken as an example for explanation.

Certain parts of the vehicle may be subjected to multiple directional loads, for example, the front control arm is subjected to loads in both the X and Y directions primarily in the ball joint position and the knuckle is subjected to loads in both the X, Y and Z directions primarily for tire contact. When dealing with the loads of these parts, it is necessary to take into account the phase relationship between the loads.

For this type of part, the step of converting the load spectrum to an equivalent load mass spectrum of sinusoidal waveform can be summarized as:

401, collecting multiple groups of time domain loads of parts in an automobile;

402, calculating the synthesis coefficient of each time domain load in the multidirectional load spectrum according to a preset synthesis coefficient calculation formula;

403, calculating a first synthesized load corresponding to each group of time domain loads according to the synthesis coefficient;

the method comprises the steps of collecting or extracting a multi-directional load spectrum of a part in an automobile, wherein the load spectrum comprises a plurality of groups of time domain load data, and each group of load needs to be repeatedly loaded for a certain number of times during testing. Each group of time domain loads is composed of a series of (multi-channel) equally spaced numerical points representing the magnitude of the load. Each channel represents a load in a different direction or load at a different load point.

According to a preset calculation formula of the synthesis coefficients, the synthesis load of each group of time domain loads in the multi-direction load spectrum is calculated, and for the time domain loads in two directions (two channels), the synthesis coefficients are shown in table 6:

TABLE 6 composite coefficients of two-directional (two-channel) loads

Wherein:

the resultant load 1 is 1 × load 1+0 × load 2;

the resultant load 2 is 0.97 × load 1+0.26 × load 2;

and calculating all the synthetic loads one by one according to the load synthetic coefficients in the table.

The resulting coefficients are shown in table 7 for loads in three directions (three channels):

TABLE 7 composite coefficients of three-directional (three-channel) loads

Wherein:

the resultant load 1 is 1 × load 1+0 × load 2+0 × load 3;

the resultant load 2 is 0 × load 1+1 × load 2+0 × load 3;

In summary, when calculating the composite load for the time domain load, the composite coefficients may be in other combinations, but all conform to the following formula:

(load 1 synthetic factor)²+ (load 2 synthetic factor)²+ … + (load I composite coefficient)²1, where I is the direction number value (number of channels) of the time domain load;

in addition, the combined load obtained by this process is taken as the first combined load in this embodiment.

404, performing cycle statistics on the first synthesized loads by adopting a four-point method to obtain a cycle composition of each group of first synthesized loads;

before the first synthesized load is subjected to cyclic statistics by adopting a four-point method, removing data points which are not inflection points from the first synthesized load of each channel, and only keeping the inflection points; the process is the same as the process of removing the non-inflection point data points in each group of time domain loads in the single direction load spectrum, and therefore, the detailed description is omitted here.

After data points of non-inflection points in the first synthesized load of each channel are removed, performing cycle statistics on the first synthesized loads by adopting a four-point method to obtain the cycle composition of each group of first synthesized loads; this process is consistent with the process of performing loop statistics on the time-domain load in processing the unidirectional load spectrum, and is not described herein again.

In the process, the calculated cyclic composition of each group of the first synthesized loads comprises cyclic compositions of loads in all directions in the multi-directional time domain loads. For example, if the time-domain load includes loads in two directions (load 1 and load 2), in this step, when calculating the cyclic composition of all the first combined loads of the time-domain load, the combined loads with the combined coefficients (1, 0) and (0, 1), that is, the combined load 1 and the combined load 7 in table 6, are included in all the first combined loads subjected to calculation, and therefore, the cyclic composition of the calculated combined load 1 and the combined load 7 is the cyclic composition of the loads in two directions (load 1 and load 2) in the time-domain load. In addition, if the time-domain loads include loads in three directions (load 1, load 2, and load 3), in this step, when calculating the cyclic composition of all the first combined loads of the time-domain loads, the combined loads having the combination coefficients (1, 0, 0), (0, 1, 0), and (0, 0, 1) are included in all the first combined loads subjected to calculation, that is, the combined loads 1, 2, and 3 in table 7, and therefore, the cyclic compositions of the calculated combined loads 1, 2, and 7 are the cyclic compositions of the loads in three directions (load 1, load 2, and load 3) in the time-domain loads.

405, calculating load range amplitude and cycle number of equivalent loads corresponding to loads in all directions in the multi-direction time domain loads;

in this process, for each direction (two directions or three directions) of the time domain load, the cycle composition of each direction of the corresponding time domain load is searched from the cycle compositions of all the first synthesized loads of the multi-direction time domain load, a load range-cumulative cycle number curve (a cycle cumulative result graph) is generated according to the cycle composition of each direction of the time domain load, and the load range amplitude and the cycle number of the equivalent load corresponding to the load in each direction of the multi-direction time domain load are estimated according to the cycle cumulative result graph. For example, the time-domain load a includes loads in two directions (load 1 and load 2), and a cyclic accumulation result graph (shown in fig. 5) of the load 1 (equal to the combined load 1 in table 6) and a cyclic accumulation result graph (shown in fig. 6) of the load 2 (equal to the combined load 7 in table 6) can be generated.

406, performing through-grade counting on the loads in all directions in the multi-direction time domain load to obtain an average value of the equivalent load, and determining a primary equivalent load block spectrum according to the average value of the equivalent load, the load range amplitude of the equivalent load and the cycle number;

carrying out through-grade counting on the loads in all directions in the multi-direction time domain load (the loads of which the load range amplitude and the cycle times are calculated in the step) to obtain an average value of equivalent loads; the process is the same as the process of performing hierarchical counting on the unidirectional time domain load, and is not described herein again.

For example, the results of the counting of the load A including two directional loads (load 1 and load 2, respectively) are shown in FIG. 7 (a graph showing the result of counting the load 1 in the two directions) and FIG. 8 (a graph showing the result of counting the load 2 in the two directions).

And generating a preliminary equivalent load block spectrum according to the load range amplitude of the equivalent load, the cycle number and the average value of the equivalent load.

407, calculating a first pseudo damage value of the multidirectional time domain load and a second pseudo damage value of the primary equivalent load block spectrum by adopting a pseudo damage value calculation formula;

408, comparing the first pseudo damage value with the second pseudo damage value to obtain a comparison result, and primarily adjusting the primary equivalent load block spectrum according to the comparison result;

in this process, the processing method for primarily adjusting the preliminary equivalent load block spectrum according to the pseudo-damage value of the time-domain load and the pseudo-damage value of the preliminary equivalent load block spectrum is the same as the processing method for adjusting the preliminary equivalent load block spectrum of the single-direction load, and therefore, the details are not repeated here.

The resulting equivalent load block spectrum results for load 1 and load 2 in time-domain load a with two directions are shown in tables 8 and 9 below:

TABLE 8 equivalent load Block spectra for load 1

TABLE 9 equivalent load Block spectra for load 2

409, adjusting the phase relation among a plurality of equivalent loads corresponding to the multidirectional time domain loads, and calculating a second synthesized load corresponding to the equivalent loads according to the phase relation and the synthesis coefficient;

410, calculating a third pseudo damage value of the first composite load and a fourth pseudo damage value of the second composite load according to a pseudo damage calculation formula;

and 411, readjusting the preliminary equivalent load block spectrum according to the phase relationship, the third pseudo damage value and the fourth pseudo damage value to generate an equivalent load block spectrum with a phase relationship.

In the above steps, the load cycle composition of each composite load of each group of time domain loads has been obtained separately, and the total pseudo damage value, i.e. the third pseudo damage value, of each composite load can be calculated according to a preset pseudo damage value calculation formula, i.e. the fatigue damage linear accumulation hypothesis (miner rule). As shown in fig. 9 (schematic diagram of the pseudo-damage values of all the synthesized loads of the time-domain load a), a group of time-domain loads a with two directions is calculated to obtain the total pseudo-damage value of the synthesized loads of all the channels.

According to the synthesis coefficients, second synthesis loads corresponding to the equivalent loads can be calculated, and the phase relation among a plurality of equivalent loads corresponding to the multidirectional time domain loads is adjusted, so that the pseudo damage value of each synthesis load (second synthesis load) synthesized by the equivalent loads according to the synthesis coefficients accords with the damage distribution rule of each synthesis load (first synthesis load) synthesized by the multidirectional time domain loads according to the synthesis coefficients. Specifically, a four-point method is adopted to carry out cycle statistics on each synthesized load synthesized by the equivalent loads to obtain a cycle composition of each synthesized load corresponding to the equivalent load, and the load range amplitude and the cycle times of the synthesized load corresponding to the equivalent load can be calculated according to the cycle composition; calculating a fourth pseudo damage value of each synthesized load synthesized by the equivalent loads according to the phase relation, the pseudo damage calculation formula, the load range amplitude of the synthesized load corresponding to the equivalent loads and the cycle number, comparing the third pseudo damage value of the synthesized load of the multi-direction time domain loads with the fourth pseudo damage value of the synthesized load synthesized by the equivalent loads, if a larger difference exists between the third pseudo damage value and the fourth pseudo damage value, namely the difference value between the third pseudo damage value and the fourth pseudo damage value is larger than a preset threshold value, adjusting the phase between the equivalent loads, and calculating the pseudo damage value of the synthesized load of the adjusted equivalent loads again; and when the difference value between the third pseudo damage value and the fourth pseudo damage value is within a preset difference value range, setting the phase relationship as the phase relationship of the equivalent load, and finally generating an equivalent load block spectrum with the phase relationship.

For example, the phase relationship between the equivalent load of the load 1 and the equivalent load of the load 2 in tables 8 and 9 is adjusted so that the fourth pseudo damage value of each combined load synthesized by the two equivalent loads according to the synthesis coefficient of the above two directional loads conforms to the damage (third pseudo damage value) distribution rule of each combined load shown in fig. 9, that is, the difference between the fourth pseudo damage value of each combined load synthesized and the pseudo damage values (third pseudo damage values) of all the combined loads of the time-domain load a in fig. 9 is within the preset difference range, and the phase relationship is set as the phase relationship of the equivalent load. Specifically, when the equivalent load phase difference between the load 1 and the load 2 in tables 8 and 9 is set to 150 degrees, the pseudo damage value of each combined load combined by the two equivalent loads is very close to the pseudo damage value of each combined load in fig. 9 and the damage error of each channel is small as shown in fig. 10 (a schematic diagram of the pseudo damage values of the combined loads of the channels when the phase difference between the two equivalent loads is 150 degrees). Therefore, the equivalent load of the load 1 and the load 2 can replace the original time-domain load, and the phase of the two equivalent loads is set to 150 degrees, so as to generate an equivalent load block spectrum.

The embodiment of the invention generates a preliminary equivalent load block spectrum by processing time domain loads in the load spectrum such as cyclic statistics, penetration counting and the like, then respectively calculates the load spectrum and the pseudo damage value of the preliminary equivalent load block spectrum, and corrects the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum; therefore, the random load spectrum is converted into the equivalent load block spectrum, the fatigue endurance test process of the automobile part is simplified, the time cost is saved, the mutual influence among a plurality of loads is considered, the phase relation among the equivalent loads is set, the characteristics of the original load are kept as far as possible by the simplified equivalent load, and the same fatigue failure mode and the same service life are excited.

Example 2

Referring to fig. 11, the present embodiment provides a load spectrum processing apparatus 100, where the load spectrum processing apparatus 100 includes:

the acquisition module 110 is configured to acquire a load spectrum of a part in an automobile, where the load spectrum includes a plurality of groups of time-domain loads;

the statistical module 120 is configured to perform cycle statistics on the time-domain load by using a four-point method to obtain a load range amplitude and cycle times;

the determining module 130 is configured to perform hierarchical counting on the time domain load to obtain an average value of equivalent loads corresponding to the time domain load, and determine a preliminary equivalent load block spectrum according to the load range amplitude, the cycle number, and the average value;

and a correcting module 140, configured to correct the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum.

The load spectrum processing apparatus described above corresponds to the load spectrum processing method of example 1. Any of the options in embodiment 1 are also applicable to this embodiment, and will not be described in detail here.

The embodiment of the present invention further provides a load spectrum processing apparatus, which includes a memory and at least one processor, where the memory stores a computer program, and the processor is configured to execute the computer program to implement the load spectrum processing method of the above embodiment.

The memory may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data (such as a pseudo damage value, an equivalent payload block spectrum, and the like) created according to the use of the payload spectrum processing apparatus, and the like. Further, the memory may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.

Embodiments of the present invention also provide a computer-readable storage medium, in which machine executable instructions are stored, and when the computer executable instructions are called and executed by a processor, the computer executable instructions cause the processor to execute the steps of the load spectrum processing method of the above embodiments.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus and method can be implemented in other ways. The apparatus embodiments described above are merely illustrative and, for example, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, each functional module or unit in each embodiment of the present invention may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention or a part of the technical solution that contributes to the prior art in essence can be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a smart phone, a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In all examples shown and described herein, any particular value should be construed as merely exemplary, and not as a limitation, and thus other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

The above-described embodiments are merely illustrative of several embodiments of the present invention, which are described in more detail and detail, but are not to be construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims

1. A method of load spectrum processing, comprising:

2. The load spectrum processing method of claim 1, wherein the load spectrum comprises a uni-directional load spectrum and a multi-directional load spectrum.

3. The load spectrum processing method according to claim 2, wherein before performing cycle statistics on the time-domain load by using a four-point method to obtain a load range amplitude and a cycle number, the method further comprises:

4. The load spectrum processing method according to claim 3, wherein when the load spectrum is a unidirectional load spectrum, the performing cycle statistics on the time-domain load by using a four-point method to obtain the load range amplitude and the cycle number comprises:

5. The load spectrum processing method of claim 4, wherein the modifying the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum comprises:

6. The load spectrum processing method according to claim 2, wherein when the load spectrum is a multidirectional load spectrum, the performing cycle statistics on the time-domain load by using a four-point method to obtain the load range amplitude and the cycle number comprises:

7. The load spectrum processing method of claim 6, wherein the modifying the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum comprises:

8. A load spectrum processing apparatus, comprising:

9. A payload spectrum processing apparatus, characterized in that it comprises a memory storing a computer program and at least one processor for executing the computer program to implement the payload spectrum processing method of any of claims 1-7.

10. A computer storage medium, characterized in that it stores a computer program that, when executed, implements a load spectrum processing method according to any one of claims 1-7.